In Japan, ventilation has always been seen as one of the main ways to keep cases low. Restaurants and bars keep their doors and windows open, busses and trains have windows open, campaigns encourage everyone to open any windows in offices and homes for ten minutes every hour... even in winter.

Seems like the science supports thi snow but for many years foreigners in Japan have traditionally and famously complained about "how stupid it is to have the windows open in winter"... the table shave turned.